1. Field of the Invention
The present invention relates to networking systems. Particularly, the present invention relates to modification of packets in a networking system for a variety of applications, including testing.
2. Background Information
Modern computer systems, especially personal computers, have gained increasing capabilities in recent years for communication. Specifically, networking technology has allowed the proliferation of such techniques as file sharing, message passing, and program linking in order to provide additional capabilities. For example, the proliferation of electronic mail has been an increased application for modern personal computer systems. Such electronic mail systems allow large numbers of users of computer systems to be linked together and communicate via messages sent over the mail system.
File sharing allows the files on one user's fixed-media device of his computer to be shared with another user's computer system. Thus, a computer system upon which files are shared becomes a "server." In this manner, data and files may be transferred to and from various systems in the network. Data and files are transmitted between computers using discrete data known as "packets." These packets follow a very specific syntax specified by the ISO-OSI reference model (Internal Standards Organization which developed and published a standard networking framework known as the Open Systems Interconnection reference model) in some computer systems.
It has been increasingly a requirement in networking systems to provide means for testing the reliability of such systems. While a network is operating, various failures may occur in the network due to various operating conditions. This causes packets transmitted in the system to become distorted or changed in some other way. For example, hardware failures may prevent a packet from traversing from one area of a network to another. In another situation, such a hardware failure may result in data loss or packet transmission errors, such as delays in transmission, multiple transmissions of same packets, packets arriving out of order, or data errors. Network traffic and/or failures may also affect the network and cause transmission errors. In fact, depending upon the failures which occur in a network, any combination of these errors may occur where packets are distorted in the network. Thus, to ensure the integrity of such systems and the related control hardware and software used in the network, testing which operates to simulate all possible error conditions which may occur is desirable. To date, no tools have existed in the personal computer industry which allow such errors to be simulated.